The present invention relates to dough processing machinery. More specifically, the present invention relates to a system for applying a fluid strip to a moving dough sheet.
In dough processing, it is often desirable to bond two or more layers of dough together. For example, in the manufacture of filled dough products a filling is applied to a moving dough sheet. The dough sheet is then folded over upon itself, and crimped or sealed in another suitable manner. For doughs of a drier nature, which are preferred for their sensory attributes when cooked, however, a bond imparted by crimping alone is usually not sufficient to withstand the stresses of cooking, handling, and eating; thus, leaks develop. Splitting of the seams and leaking of the filling are serious consumer issues with filled dough products. To increase the effectiveness of the bond of the seams, attempts have been made to apply fluid to the surface of the dough.
The application of fluid to a moving dough sheet has traditionally been accomplished by means of an atomizing spray, a waterfall, or by droplets. However, all methods pose problems either because of the excess amount of fluid applied or because of inadequate coverage of the fluid.
The spraying method does not allow precise control of the amount of fluid actually delivered to the dough because only a portion of the fluid is actually delivered to the dough surface. The amount actually delivered to the dough varies, depending on the relative humidity. Generally, more fluid is required to be supplied than is actually delivered. Also, the spraying method atomizes the fluid which causes tiny airborne droplets to reside in the area of production. This enhances the possibility of microbial growth and contaminants contacting the dough, and can increase the humidity in the processing environment. Increased moisture is particularly detrimental in processing areas that are preferably kept dry or where humidity is carefully controlled for optimum performance. Additionally, in a dough processing plant a fine layer of flour usually exists on virtually all surfaces and atomizing spray tends to turn the fine layer of flour into a sticky layer which is not only aesthetically undesirable, but also contributes to microbial growth. These microbial concerns create food safety problems with the use of sprays in food manufacturing applications. One alternative to the spraying method is described in a co-pending application entitled "LIQUID DISTRIBUTION APPARATUS FOR A DOUGH PROCESSING LINE" filed on even date herewith having Ser. No. 08/720,023, now U.S. Pat. No. 5,855,670.
The waterfall method, although not subject to the food safety concerns of the spray method, has problems of its own. The waterfall method requires the application of a steady stream of fluid. The minimum amount of fluid required to apply a steady stream is more than the maximum amount of fluid that the dough can accept without adverse consequences. The resulting over hydration yields gummy sensory attributes in the dough making the dough difficult to work with. The excess water also exacerbates concerns related to microbial growth.
The fluid droplet method is similar to the waterfall method except that, instead of applying a steady stream of fluid to the dough, discrete drops of fluid are provided to the dough. If the frequency of the drops is low enough, the dough does not become over-hydrated as it does with the waterfall method. However, applying discrete fluid droplets at such a low frequency results in inconsistent coverage. In other words, using the fluid droplet method, it is very difficult to obtain a consistent and continuous fluid strip along the dough surface without over hydrating the dough.